Therefore, do you think it really matters? Can not having enough RAM (for some weird reasons) cause rigs to be instable and/or driver crashes?
Has nothing to do with what anyone thinks, it's like you'd ask us if we think 1+1 equals 2.
RAM will only matter if you're using Reaper as your mining software, otherwise (using cgminer, sgminer, etc) it has really minimal effect on your rig and you can easily run your mining rig with as little as 2GB of RAM.
The only reason adding RAM solves anyone's problem is because they misconfigured their rig to begin with.
Right before I bought my R9 290s I searched the forum a lot about the card and I remember seeing a whole thread with dozens of replies saying how the R9 290s require a lot of RAM for them to work properly (and I mean a lot - 8 to 16GB lol). I then got lucky enough to chat with a guy who has a big mining farm with a few R9 290 and he told me he doesn't need more than 2GB to run any of his rigs.
Needless to say, once I got my R9 290s I got them to work flawlessly with 4GB of RAM (which I already had from an old PC - if I'd buy, I'd buy only 2GB) and when you check system processes you can see that less than 2GB is being used at any given time.
